Jesse Lingard took his goal tally to eight in nine appearances since joining West Ham on loan from Manchester United by netting twice in a 3-2 victory over Leicester on Sunday.
The win allowed West Ham to dislodge Chelsea and move back into fourth place in the Premier League in pursuit of Champions League qualification for the first time.
David Moyes’ side held off a late Leicester fightback and is now just a point behind third-place Leicester. Leicester’s cause was not helped by a breach of COVID-19 rules by some of their players.
“Those involved have apologized for their poor judgement," Leicester said. "Our response to the matter will be concluded internally.”
James Maddison, Hamza Choudhury and Ayoze Perez were all left out for what could potentially end up being a pivotal clash for the European aspirations of both teams.
A moment of quality from the in-form Lingard, in front of England boss Gareth Southgate, put West Ham ahead in the 29th minute.
Right back Vladimir Coufal cut the ball back to Lingard, who sent a precise volley past goalkeeper Kasper Schmeichel from the edge of the area.
Lingard struck again in the 44th when the Leicester defense was caught out by a long ball from Issa Diop. Jarrod Bowen stayed just onside as he raced toward goal and, as Schmeichel came out, the winger squared for Lingard to tap into an empty net.
The hosts were 3-0 up just three minutes into the second half after Arthur Masuaku robbed Kelechi Iheanacho and fed Lingard down the left. Lingard cut the ball back to Tomas Soucek, who played it on to Bowen for a simple finish from eight yards (meters).
But West Ham have found 3-0 leads hard to hold onto in recent matches, having been pegged back to 3-3 by Arsenal and clung on for a 3-2 win at Wolves on Monday.
The jitters threatened to set in again when Masuaku lost possession and Iheanacho lashed home.
Ricardo Pereira should have halved the remaining deficit when he was played in by Youri Tielemans but Lukasz Fabianski thwarted the full back. Iheanacho did grab a second when he prodded in Marc Albrighton’s cross at the start of six minutes of stoppage time.
Wesley Fofana then headed a last-gasp chance wide as West Ham held on to inflict only a second away defeat of the season on the Foxes.